Nonapeptide levels in male cleaner fish brains during interactions with unfamiliar intra and interspecific partners

Behavioral Ecology and Sociobiology - A growing body of research suggests that songs are an important part of the courtship behavior of many bat species, however there is little information on the...     

Optimization of conventional Fenton and ultraviolet-assisted oxidation processes for the treatment of reverse osmosis retentate from a paper mill

According to current environmental legislation concerned with water scarcity, paper industry is being forced to adopt a zero liquid effluent policy. In consequence, reverse osmosis (RO) systems are being assessed as the final step of effluent treatment trains aiming to recover final wastewater and reuse it as process water. One of the most important drawbacks of these treatments is the production of a retentated stream, which is usually highly loaded with biorecalcitrant organic matter and inorganics; and this effluent must meet current legislation stringent constraints before being ultimately disposed. The treatment of biorefractory RO retentate from a paper mill by several promising advanced oxidation processes (AOPs) - conventional Fenton, photo-Fenton and photocatalysis - was optimized considering the effect and interaction of reaction parameters; particularly using response surface methodology (RSM) when appropriate (Fenton processes). The economical cost of these treatments was also comparatively assessed. Photo-Fenton process was able to totally remove the COD of the retentate, and resulted even operatively cheaper at high COD removal levels than conventional Fenton, which achieved an 80% reduction of the COD at best. In addition, although these optimal results were produced at pH=2.8, it was also tested that Fenton processes are able to achieve good COD reduction efficiencies (>60%) without adjusting the initial pH value, provided the natural pH of this wastewater was close to neutral. Finally, although TiO(2)-photocatalysis showed the least efficient and most expensive figures, it improved the biodegradability of the retentate, so its combination with a final biological step almost achieved the total removal of the COD.     

Population dynamics, sex ratio and size at sex change in a protandric simultaneous hermaphrodite, the spiny shrimp Exhippolysmata oplophoroides

One of the main goals of sex allocation theory is understanding sex ratio evolution. However, theoretical studies predicting sex ratios in species with unusual sexual systems, such as protandric simultaneous (PS) hermaphroditism, are rare. In PS hermaphrodites, juveniles first develop into functional males that mature into simultaneous hermaphrodites later in life. Here, we report on the sex ratio (males/males + hermaphrodites) in the PS hermaphroditic shrimp Exhippolysmata oplophoroides. A 2-year study demonstrated that hermaphrodites dominated the population in two different bays. This skewed sex ratio may be explained by limited encounter rates among conspecifics. In agreement with this idea, the density of shrimps was extremely low (≤1 shrimp km⁻²) at the two study sites. Size at sex phase change and sex ratios remained relatively stable through time at the two bays. The stability of these parameters might be explained by the rather steady population structure of this species during the study period. A review of sex ratios in PS hermaphroditic shrimps (Lysmata and Exhippolysmata) revealed considerable variation; some species have male- and others hermaphrodite-skewed sex ratios. The conditions explaining inter- and intra-specific sex ratio variation in protandric simultaneous hermaphroditic species remain to be addressed.     

Risk level of chemical cues determines retention of recognition of new predators in Iberian green frog tadpoles

In aquatic environments, many prey rely on chemosensory information from injured (alarm cues) or stressed conspecifics (disturbance cues) to assess predation risk. Alarm cues are considered as a sign of higher risk than disturbance cues. These cues could be used by prey to learn potential new predators. In this study, we tested whether Iberian green frog tadpoles (Pelophylax perezi) exhibited antipredator responses to alarm and disturbance cues of conspecifics and whether tadpoles could associate new predators with alarm or disturbance cues. Tadpoles reduced their activity in the presence of disturbance cues, but only weakly when compared with their response to alarm cues. Also, tadpoles learned to recognize new predators from association with alarm or disturbance cues. However, the period of retention of the learned association was shorter for disturbance than alarm cues. Our results indicate that tadpoles are able to modify their antipredatory behavior according to (1) the degree of risk implied by the experimental cues (2) their previous experience of chemical cues of the predator.     

Electrophysiological responses and field attraction of the grey corn weevil, Tanymecus (Episomecus) dilaticollis Gyllenhal (Coleoptera: Curculionidae) to synthetic plant volatiles

The grey corn weevil, Tanymecus (Episomecus) dilaticollis, is an economically important polyphagous pest in Eastern and Central Europe. The present research is the first published electrophysiological study of olfactory sensitivity of adult T. dilaticollis to plant volatiles. The electrophysiological responses of male and female antennae were recorded to 20 synthetic volatile organic compounds (VOCs), previously identified to be released from the preferred host plants, maize and sunflower. Antennae of both sexes responded to a wide range of volatiles from different chemical classes: fatty acid derivatives, aromatic compounds and terpenoids. Two green leaf volatiles, (E)-2-hexen-1-ol and (Z)-3-hexen-1-ol, and one terpenoid, (±)-linalool, elicited the strongest electrophysiological responses by male and female antennae. Relatively high electrophysiological activity by T. dilaticollis antennae was also recorded to benzaldehyde, eugenol and caryophyllene. In the field, (E)-2-hexen-1-ol and (Z)-3-hexen-1-ol, when presented individually, caught significantly more male and female T. dilaticollis than unbaited controls. These compounds could be developed into an attractive trap for the detection and monitoring of T. dilaticollis.     

Egg-spot pattern rather than egg colour affects conspecific egg rejection in the house sparrow (Passer domesticus)

Brood parasitism could be a selective pressure on each female to have a type of egg that permits recognition. House sparrows (Passer domesticus) undergo conspecific brood parasitism and can recognise parasitic eggs. In this study, we analyse the effect of relative size in experimental parasitic eggs compared to the host eggs. We modified egg colour and the spot pattern to determine the influence of these characteristics on egg rejection. Furthermore, we examine whether egg rejection increases with “stimulus summation”. Our results show that egg rejection is not affected by relative egg size. However, changes in the spot pattern proved to exert the highest influence on egg rejection (32.4% of trials), significantly higher than when only egg colour is changed (3.8%). Therefore, our results suggest that parasitism may be a pressure favouring the maintenance of spotted eggs in house sparrow.     

Facilitating biodiversity conservation through partnerships to achieve transformative outcomes

Conservation biology is a mission-driven discipline that must navigate a new relationship between conservation and science. Because conservation is a social and political as well as an ecological project, conservation biologists must practice interdisciplinarity and collaboration. In a comparative study of 7 cases (Jaguars in the Chaco, Grevy's zebra in Kenya, Beekeeping in Tanzania, Andean cats in Argentina, Jaguars in Mexico, Lobster fishing, and Black bears in Mexico), we examined motivations for collaboration in conservation, who can collaborate in conservation, and how conservation professionals can work well together. In 5 case studies, successful conservation outcomes were prioritized over livelihood benefits. In the other 2 cases, livelihoods were prioritized. All case studies employed participatory approaches. There were multiple external actors, including local and Indigenous communities, nongovernmental organizations, agencies, regional and national governments, and international organizations, which enhanced conservation and wider sustainability outcomes. Key collaboration aspects considered across the case studies were time (mismatch between relationship building and project schedules), trust required for meaningful partnerships, tools employed, and transformative potential for people, nature, and the discipline of conservation biology. We developed guidelines for successful collaboration, including long-term commitment, knowledge integration, multiscalar and plural approaches, cultivation of trust, appropriate engagement, evaluation, supporting students, and efforts for transformation.     

A roadmap for ladybird conservation and recovery

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.     

Road safety performance indicators and their explanatory value: A critical view based on the experience of Central European countries

Counts of road crashes and their victims represent essential information for road safety practitioners allowing them to analyse their spatial and temporal aspects. However, they cannot provide details on the factors causing road crashes. As a result, various road safety performance indicators (RSPIs) were introduced, making it possible to gather information on the effectiveness of interventions on road safety in given areas. However, analysis of the trends in road casualties in several Central European countries based on safety performance (measured by RSPIs) suggest that not even these indicators can provide full understanding of road safety trends, and, if they are applied generally without the required background information, this could even lead to serious misinterpretation of the trends in road casualties. Sudden breaks in long-term trends seem to be linked to the transition process and to certain legislative reforms. The exposure and socio-economic climate appear to have had a major impact on road crash outcomes. Various additional indicators describing organisational and structural aspects may be helpful, therefore, in better understanding and predicting the development in road safety for individual countries.     

Mapping residual pyrite after a mine spill using non co-located spatiotemporal observations

Monitoring of soil chemical properties for pollution assessment generally requires destructive soil sampling and results in spatiotemporal datasets where data from different sampling dates are non co-located. The objective of this study was to assess the spatial distribution of residual pyrite sludge at a reclaimed site, using temporally non co-located data on pH; soil oxidizable fraction (SOF); and EDTA-extractable Fe, Zn, and Cu from six different sampling dates over a period of 2 yr. During this period spatially averaged pH and Zn concentrations ranged, respectively, from 4.4 to 6.6 and from 60 to 140 mg kg(-1), with minimum pH values of below 2.7. The data were merged into a single dataset for each chemical property after applying a normal score (ns) transform. Normal score pH was significantly negatively correlated with the ns metal concentrations. A principal component analysis (PCA) showed that normal score pH, Zn, and Fe were associated with the residual contamination, while ns Cu, SOF, and elevation were related with historic contamination. The spatial dependence between the properties was found to be scale-dependent. The best ns estimates were produced by ordinary kriging with an anisotopic variogram model, for the properties related with Principal Component (PC) I, while those associated with PC II were best estimated using simple kriging with varying local means. A classified ns pH map showed that 33% of the study area reached at least once values of below 4 during the 2-yr period. This part of the area should be excluded to ensure successful revegetation.